The performance of porous ceramsites in a biological aerated filter for organic wastewater treatment and simulation analysis

Porous ceramsites were prepared using the high silicon iron tailings as the matrix. The specific surface area, bulk density and porosity of the obtained porous ceramsites are 5.54 m(2)/g, 0.78 g/cm(3) and 49.8 %, respectively. Subsequently, biofilm was inoculated and domesticated on the surface of ceramsites in a biological aerated filter (BAF) for the removal of organic pollution in water. The removal rates of chemical oxygen demand (COD), ammonia (NH3-N), and total phosphorus (T-P) in the organic wastewater were 91 %, 85 %, and 80 % respectively. It was found out that during the maturation diffusion period, the pore size between ceramsites had a significant impact on the biofilm adhesion growth and the effect of degradation organic matter. In addition, in order to better understand the removal mechanism of biofilm for COD, NH3-N and T-P, an analytical model for the flow field and resistance characteristics between pores of biofilm was established, which may provide more valuable references for the practical utilization of porous ceramsites.